Paper supply trays are used in printers, such as ink-jet or laser printers, to support and align the media for feeding into the printer. The paper supply tray aligns the paper in two dimensions, width and length. In operation, a paper stack is manually placed in the paper supply tray. The tray is then securely positioned adjacent the printer. This positioning places the paper stack adjacent the paper picking mechanism within the printer. The paper picking mechanism operates by picking the top sheet from the stack and forcing the sheet into the printer.
In the art of printing it is desirable for the printer to accommodate different sizes of paper or other media such as overhead projector transparency film. Examples of papers with different dimensions include: "A" size, 81/2 inch.times.11 inch, commonly referred to as U.S. letter size; "A4" size, 210 mm.times.297 mm, commonly referred to as international letter size; and 81/2 inch.times.14 inch, commonly referred to as legal size.
It is important that the width and length dimensions of the paper are correctly aligned in the supply tray. Lack of proper alignment can prevent the paper from being fed into the printer feed mechanism or cause the paper to be fed in a skewed orientation. This skew, in turn, can lead to either a jam in the feed mechanism or a distorted printed page. Several methods have been used by printer manufacturers to address the problem of matching the paper supply tray to different sizes of paper. In one approach, a unique tray is designated for each paper size that the printer accommodates. This will insure that the right size paper is inserted in a given tray. This approach, however, has several disadvantages. The disadvantages to the manufacturer or reseller are increased cost in molding numerous sized and configured trays, and increased cost in maintaining inventory of multiple trays. To the user, the disadvantages include storing trays not presently in use; purchasing, often at an additional cost, trays which are not initially provided with the printer; and interchanging of paper trays to accommodate different sizes of paper.
Another approach, allows the manufacturer to produce one paper supply tray that can be configured for the various sizes of paper. This approach reduces manufacturing cost by requiring only one mold for all paper trays. However, these trays require two separate adjustments, one to adjust for the length and the other to adjust for the width of the paper. Two adjustments are not only cumbersome, but also many times the user does not change the width adjustment either out of unawareness or forgetfulness. Lack of correct adjustment, as stated above, can prevent the paper from being fed into the printer or cause the paper to be fed in a skewed orientation.
It will be apparent from the foregoing that although there are many paper supply tray apparatus for supporting and aligning media, there is still a need for a design that provides low manufacturing cost and ease of use.